Hermetically sealed manual disconnect

ABSTRACT

A hermetically sealed, high voltage manual disconnect that can be manually operated from outside the disconnect to transition between connect and disconnect states. The disconnect comprises a hermetically sealed housing having internal components for changing the state of the disconnect. A gas can fill the housing to allow for reliable high voltage operation. Different embodiments of the manual disconnect can include electrical and electronic components so that the state of the disconnect can be changed in response to an electrical signal.

This application is a divisional of, and claims the benefit of, U.S.application Ser. No. 13/654,882, to Mike Molyneux, et al., entitledHERMETICALLY SEALED MANUAL DISCONNECT, which claims the benefit ofprovisional application No. 61/548,599 to Molyneux, which was filed onOct. 18, 2011, and also claims the benefit of provisional applicationNo. 61/706,041 to Molyneux, which was filed on Sep. 26, 2012.Provisional application 61/548,599, provisional application 61/706,041and U.S. application Ser. No. 13/654,882, including their drawings,schematics, diagrams and written description, are hereby incorporated intheir entirety by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to manual disconnects, and particularly tohermetically sealed manual disconnects.

2. Description of the Related Art

Manually connecting and disconnecting electrical circuits is as old aselectrical circuits themselves, and is the way circuits are connected ordisconnected if relays or contactors or other electrically operatedswitches are not used. In high power applications, or where a user needsto be assured that an electrical source is isolated, manually operateddisconnects can be used. As voltages and currents have increased inmodern day applications like electric vehicles or solar generation, themanual disconnects, if used, need to be very large to be able topractically disconnect higher power loads.

Because of their small size and weight, hermetically sealed disconnectscan be used in high power applications, with these conventional sealeddisconnects being electrically operated. Users may still want tomanually disconnect a disconnect in these high power applications to beassured of the isolation. However, these conventional electricallyoperated hermetically sealed products do not provide for a manualdisconnect option, as it is difficult to provide manual positiveoperation without compromising the hermetic seal of the disconnect.

SUMMARY OF THE INVENTION

The present invention provides hermetically sealed, high voltage manualdisconnects that can be manually operated from outside the disconnect tochange from the connect to the disconnect state. The disconnectcomprises a hermetically sealed housing having internal components forchanging the state of a relay. A gas can fill the housing to allow forreliable high voltage operation, with the housing made of a materialthat is substantially impermeable to the gas. Different embodiments ofdisconnects according to the present invention can also compriseelectrical and electronic components so that the state of the disconnectcan be changed both manually and in response to an electrical signal.

These and other further features and advantages of the invention wouldbe apparent to those skilled in the art from the following detaileddescription, taking together with the accompanying drawings, in which:

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional view of one embodiment of a manually operatedsealed disconnect according to the present invention;

FIG. 2 is a sectional view of another embodiment of a manually operatedsealed disconnect according to the present invention;

FIG. 3 is a sectional view of another embodiment of a manually operatedsealed disconnect according to the present invention;

FIG. 4 is a sectional view of another embodiment of a manually operatedsealed disconnect according to the present invention;

FIG. 5 is a sectional view of another embodiment of a manually operatedsealed disconnect according to the present invention;

FIG. 6 is a perspective view of a handle mechanism as might be used witha manually operated sealed disconnect according to the presentinvention;

FIG. 7 is a side view of another embodiment of a manually operatedsealed disconnect according to the present invention;

FIG. 8 is a top view of the disconnect shown in FIG. 7; and

FIG. 9 is a bottom view of the disconnect shown in FIG. 7.

DETAILED DESCRIPTION OF THE INVENTION

The present invention provides a low cost, high-power, manual disconnectin a hermetically sealed housing. The disconnect can comprise amechanism for manual operation that allows for a user, such as anoccupant of a vehicle, to manually change the state of the disconnectbetween connect and disconnect states, and thus affect the operation ofan electric circuit coupled to the disconnect. This manual change ofstate can be accomplished without compromising the hermetic seal of thedisconnect. This manual mechanism can also be included in disconnectshaving electrical connectors to change the state of the disconnect by anelectrical signal to allow for disconnects that can change from connectto disconnect either manually or in response to an electrical signal.

The mechanisms that result in the state changes can be operable bydifferent motions, including but not limited to linear or rotationalmovement. Many different mechanisms can be used, including but notlimited to rotational or linear magnetic feed-throughs, or rotational orlinear mechanical feed-throughs. It is understood that these are only afew examples of the many manual mechanisms that can be used inembodiments according to the present invention.

In some embodiments, the housing includes a flat, low cost ceramicheader that provides an airtight seal. This allows the header to bemanufactured using low cost materials and processes, while stillproviding a housing that can be gas filled under pressure to providereliable high voltage operation through a long life cycle. The flatceramic header also provides for inexpensive tooling, simplemetallization and uncomplicated manufacturing processes while providingelectrical isolation between the contacts.

In some embodiments, the header is not made of ceramic but insteadcomprises an epoxy material. There are several kinds of epoxy materialswhich bond satisfactorily with the materials that can be used for thehousing (including plastic and metal) and which can provide an airtightseal due to their impermeability. This prevents leakage of air intointernal vacuum conditions and loss of insulating gas under internalpressurized conditions. Examples of such epoxy header materials can befound in U.S. patent application Ser. No. 09/773,997, filed on Jan. 31,2001, which published as US Patent Publication US 2002/0097119 A1 onJul. 25, 2002, which is hereby incorporated in its entirety byreference, including the drawings, corresponding descriptions anddisclosure regarding the use of epoxy compounds for providing hermeticseals. It is understood that the header can be comprised of manydifferent materials suitable for providing an air tight seal and thatthe present disclosure and descriptions of various embodiments are notlimited to specifically described arrangements and materials.

The invention below is described in relation to different embodiments ofmanual disconnects according to the present invention, but it isunderstood that the invention can be used with other disconnects ordevices, and that the disconnects below can have different componentsarranged in different ways.

It will be understood that when an element or component is referred toas being “on”, “connected to”, “coupled to” or “in contact with” anotherelement or component, it can be directly on, connected or coupled to, orin contact with the other element or component or intervening elementsor components may be present. In contrast, when an element is referredto as being “directly on,” “directly connected to”, “directly coupledto” or “directly in contact with” another element or component, thereare no intervening elements or components present.

FIG. 1 shows one embodiment of a manually operated low cost, high-powerdisconnect 100 according to the present invention comprising a housing102 having an outer cup 104 and a flat header 106. The disconnect'sinternal moving components can be arranged on the header 106 as furtherdescribed below, and the header 106 is sized and arranged to mate withand mount in the opening of the cup 104 such that there is a hermeticseal between the two. The disconnect's internal moving components areheld in the sealed internal chamber defined by the header 106 and thecup 104. The chamber can be filled with gas by an air tube (not shown)that passes through the header 106. Alternatively, the air tube can beused to form a vacuum within the chamber. The disconnect's internalcomponents are also contacted through the header 106. The disconnect 100also comprises a manual mechanism 108, which can be mechanical, formanually changing the state of the disconnect, with some embodimentsrelying on a rotational/axial feed through as described in more detailbelow. The mechanism 108 operates while still maintaining a sealeddisconnect housing 102, thereby allowing the disconnect 100 to maintainits vacuum or gas.

The internal components of the disconnect 100 further comprise a plunger110, a plunger spring 112, a plunger shaft 114 (which can be hollow),contact springs 116, substantially circular plate 118, and at least onemoveable contact 120. Moveable contact 120 can comprise a single contactor multiple contacts arranged to operate in conjunction with one anothersuch that when moveable contact 120 moves, the multiple contacts willmove together.

The shaft 114 goes through the middle of the plunger 110 with theplunger spring 112 held between the lower portion of the plunger 110 andcircular plate 118. When the manual mechanism is operated as describedbelow, the plunger 110 moves moveable contact 120 towards fixed contacts122, 124 and the plunger spring 112 is compressed between the lowerportion of the plunger 110 and the circular plate 118. When the manualmechanism operates in the opposite direction, and the plunger 110 movesaway from the fixed contacts 122, 124, the plunger spring expands. Inembodiments incorporating a hollow shaft, plunger shaft 114 enables theplunger 110 to move readily in a sealed environment, as the hollow shaft114 allows any gas within the sealed housing 102 to flow freely throughthe plunger 110 and the pressure to equalize during the travel ofplunger 110.

When activating the manual mechanism to place the disconnect in theconnect state, the plunger moves moveable contact 120 a certain distanceknown as the “contact gap” before it makes contact with fixed contacts122, 124. The contact gap is the distance between moveable contact 120and fixed contacts 122, 124 which provides electrical isolation toprevent current flow when movable contact 120 is not in contact with thefixed contacts 122, 124. When the movable contact 120 is in contact withfixed contacts 122, 124, a conductive path is formed between first andsecond external terminal studs 126, 128, which are typically connectedto the fixed contacts 122, 124. The terminal studs 126, 128 can belocated externally to the housing 102 in different embodiments, but itis understood that the terminal studs 126, 128 may be arranged in anumber of different ways.

In some embodiments, after moveable contact 120 makes contact with fixedcontacts 122, 124, the plunger 110 continues to move and compressesfirst contact spring 116. This additional post-contact movement of theplunger is known in the art as plunger overtravel. The compression forceof first contact spring 116 is applied to the contacts through theinitial part of the plunger overtravel. In one embodiment, plungerspring 112 has a lower spring rate than contact spring 116.

In different embodiments, the manual mechanism is arranged such thatcomponents inside the housing are used in cooperation with componentsexternal to the housing. In some of these embodiments, a magnetic forceor attraction between the internal and external components feeds throughthe housing (without compromising the housing) allowing movement of theexternal components to cause movement of the internal components.

In disconnect 100, manual mechanism 108 relies on a rotational/axialfeed through mechanism which allows for the state of the disconnect tobe changed without having a mechanical connection between the manualmechanism components and the disconnect's internal components. In oneembodiment according to the present invention, a magnetic field is usedto impart movement to the disconnect's internal components when themanual mechanism is rotated. This arrangement allows for changing thestate of the disconnect without having a mechanism that passes throughhousing 102 of the disconnect. This allows for the present invention tomaintain a sealed housing, which can allow the housing to hold a largervacuum, or for the housing to hold a gas under higher pressure. Thisarrangement can also result in smaller devices with higher ratings.

In one embodiment, the manual mechanism can comprise a plunger bar 130mounted to the plunger 110, with both components being internal to thedisconnect's housing 102. The plunger bar 130 is located near the top ofthe housing 102, with first and second magnets 132, 134 mounted atopposing ends of the bar 130. The magnets 132, 134 can be mounted inmany different locations, with the embodiment shown having the magnets132, 134 facing the top inner surface of the housing 102. The bar can bemade of many different rigid materials such as a metal, plastic orceramic, and can comprise a single bar, as shown in FIG. 1, or multiplebars. The bar 130 can be mounted to the plunger 110 with a rigidconnection so that rotation of the bar causes rotation of the plunger110 within the housing 102.

Rotation of the plunger bar 130 is caused by the force of one or moreexternal magnetic fields drawing the magnets 132, 134 in a rotationalmotion. Many different arrangements can be used to provide this externalmagnetic field, and in the embodiment shown, an external magnetic bar136 is arranged on top of the housing 102 in an opposing fashion to theplunger bar 130. The external bar 136 is mounted to the housing 102 suchthat it can be rotated about the top of the housing 102, preferably bymeans of a pivot 138. The plunger bar 130 can comprise magnets toprovide the external magnetic field to cause rotation of the plunger bar130, and in the embodiment shown the first and second external magnets140, 142 are mounted to the underside of the plunger bar 130, facing theplunger bar magnets 132, 134 through the housing 102. The magnetic fieldfrom the plunger bar's first and second external magnets 140, 142interacts with the magnetic field of the plunger bar magnets 132, 134,such that there is a magnetic attraction between the magnets. As theexternal bar 136 is rotated, the magnetic field between the plunger barmagnets 132, 134 and the external magnets draws the plunger bar 130 torotate with external bar 136.

In other embodiments, first and second external magnets 140, 142 can beconfigured such that an opposing magnetic field between plunger barmagnets 132, 134 and first and second external magnets 140, 142 isprovided. In this embodiment, the magnetic field between the plunger barmagnets 132, 134 and the external magnets causes the plunger bar 130 torotate in opposition to external bar 136. In another embodiment, plungerbar magnets 132, 134 and first and second external magnets 140, 142 canbe arranged such that there is an opposing magnetic field between themsuch that the external magnetic bar can be pushed closer to housing 102,thus changing the position of plunger bar magnets 132, 134, andtherefore plunger bar 130. It is understood that the external magnetscan be arranged in many different ways beyond being mounted to anexternal bar, and like the plunger bar 130, the external bar cancomprise multiple pieces mounted to the housing in many different ways.

In some embodiments, rotation of the plunger bar 130 can cause rotationof the plunger 110. The plunger 110 can be arranged with many differentmechanisms that translate rotational movement of the plunger bar 130 tolinear motion of the plunger 110. In the embodiment shown, the plunger110 can comprise one or more tabs 144 on a surface of the plunger 110and arranged to cooperate with one or more slots 146. The slot 146 canbe shaped or angled so that as the plunger 110 is rotated, thecooperation of the tabs 144 in the slots 146 causes the plunger 110 tomove linearly within the housing 102; i.e. between the top and bottom ofdisconnect 100 depending on the direction of rotation. This causes thedisconnect to be moved between connect and disconnect states.

In some embodiments, the plunger and shaft can be arranged so thatrotation of the plunger 110 does not cause rotation of the shaft 114,but linear movement of the plunger 110 causes linear movement of theshaft 114. In other embodiments, plunger 110 and shaft 114 can rotate inunison while not causing rotation of the movable contact 120. It isunderstood that these are only some of the many arrangements that can beutilized in disconnects according to the present invention.

Header 106 can take many different shapes, but in the embodiment showncomprises a flat shape to help make tooling inexpensive, themetallization simple, and the post processes less complicated. Header106 is preferably made of ceramic or epoxy material, although othermaterials resistant to high temperatures may also be used. Header 106comprises first and second contact holes 148, 150 sized so that externalstuds 126, 128 can pass through the header 106 to make electricalcontact with fixed contacts 122, 124. The contact holes 148, 150 and theouter rim of the header 106 are preferably coated with an electricallyconductive material, with a preferred conductive material comprising ametal such as copper.

Different embodiments can also comprise sealed tubes arranged to allowgasses to be injected into the housing, preferably under pressure, or avacuum to be created in the housing. After the gasses are injected (orvacuum conditions created), the tube is sealed so that no further gassescan pass in or out. The cup 104 and header 106 are preferably made of amaterial having low or substantially no permeability to the gas injectedinto the housing, with the cup 104 being made from a metal such as ironand flat header 106 preferably made from ceramic or epoxy material. Manydifferent gasses can be injected into the housing 102, with thepreferred gas being hydrogen because it protects the copper fromoxidation, keeps the contacts clean, and keeps contact resistance low.

To provide a hermetically sealed housing 102, the inner cup 104 can bearranged with a flange 152 around the edge of its opening. A headerbraze assembly 154 is arranged with a complimentary flange 156, and issized so that both flange 152 and 156 can rest on one another. O-rings158 are included around each of the contact holes 148, 150 to ensurethat a seal is formed at each of the holes at the header 106. TheO-rings 158 are preferably suited to high temperature applications, andare used to seal arc chamber 160. The seal prevents internal componentsin the arc chamber 160 can reach other metal parts outside the arcchamber 160.

Some disconnect embodiments can also comprise a solenoid for electricaloperation that allows for the disconnect to change states both manuallyand electrically. The solenoid can be energized by applying anappropriate bias through auxiliary contact lead wires (not shown). Thiscan cause the movable contact 120 to contact the fixed contacts 122, 124to form a conductive path between first and second external terminalstuds as described above for manual operation. Many different solenoidscan be used, with a suitable solenoid operating under a low voltage andwith a relatively high force. One example of a suitable solenoid iscommercially available solenoid Model No. SD1564 N1200, from BicronInc., although many other solenoids can be used.

As mentioned above, many different manual mechanisms can be used indisconnects according to the present invention. FIG. 2 shows anotherembodiment of a disconnect 200 that is similar to disconnect 100; forsimilar features, the same reference numbers from FIG. 1 are used inFIG. 2. The disconnect 200 comprises a housing 102, inner cup 104, andheader 106, arranged as described above to hold the disconnect'sinternal components. The shaft 114 is arranged so that is passes throughthe housing 102, with the portion of the tube extending from the housingbeing arranged in a shaft tube 202. In some embodiments the tube 202 issealed and is mounted to the housing with a seal. This allows thedisconnect 200 to hold a gas or vacuum without leaking to the ambientthrough the tube.

The shaft 114 can have a plunger spring 112, and a contact spring 116included in the housing 102. Shaft 114 or plunger 110 can be made of amaterial that is attracted to magnets, or can comprise a magnet (notshown) mounted on or near the shaft 114 such that movement of the magnetcauses movement of the shaft 114. The disconnect 200 comprises one ormore external magnets 204 that are around the tube 202, with themagnetic field from the external magnets causing a magnetic attractionbetween the external magnets and the shaft 114. As magnets 204 are movedup and down the tube 202, the shaft also moves up and down, causing thedisconnect to change between connect and disconnect states. As discussedabove, it is also understood that there are embodiments whereinmovements of external magnets causing a magnetic repulsion via anopposing magnetic field can cause movement of the shaft 114.

Many different mechanisms can be used to cause movement of the externalmagnets up and down the tube, such as a handle that provides a pull andpush movement to move the magnets. Alternatively, a rotation mechanismcan be used that is arranged to translate rotational movement to linearmovement.

FIG. 3 shows a disconnect 300 that utilizes opposing magnets to controlthe movement of shaft 114. The disconnect 300 comprises a housing 102,inner cup 104, and header 106, arranged as described above to hold thedisconnect's internal components. The shaft 114 is arranged so that ispasses through the housing 102, with the portion of the shaft extendingfrom the housing being arranged in a shaft tube 202. Disconnect 300further comprises an external magnet 302 and an internal magnet 304which are arranged such that there is an opposing magnetic field betweenthem. Manual mechanism 108 can contain or be attached to external magnet302 and be arranged to move linearly, sliding along bearings 306.Bearings 306 can be made of many different materials, including but notlimited to Teflon, iron and plastic. Internal magnet 304 can be attachedto or arranged with shaft 114 or can be attached to or function as aplunger as described above, such that movement of internal magnet 304causes movement of shaft 114.

During operation of disconnect 300, manual mechanism 108 is pusheddownward, causing it to move along bearings 306 such that externalmagnet 302 nears the position of internal magnet 304. The opposingmagnetic field pushes internal magnet 304 downward which causes shaft114 to move downward, causing moveable contact 120 to contact fixedcontacts 122, 124, causing disconnect 300 to enter a connect state.Adjusting manual mechanism 108 upward reduces the opposing magneticfield, allowing shaft 114 to return to its original position. The returnof shaft 114 to its original position can be assisted by first andsecond contact springs 308, 310.

First and second contact springs 308, 310 can be arranged in variousways. In one embodiment, first and second contact springs 308, 310 arearranged in the same location, with first contact spring 308 nestedinside second contact spring 310. This embodiment can increase the forceof the contacts at the end of plunger overtravel, which can improve theelectrical performance of the disconnect. In this embodiment, thecompression force of the first contact spring is applied to the contactsthrough the initial part of the plunger overtravel. As external andinternal magnets 302, 304 approach the end of plunger overtravel, thereis a significant rise in magnetic force. In order to take advantage ofthis force, second contact spring 310 is activated. First contact spring308 can be preloaded and have a lower spring rate, while second contactspring 310 can be not preloaded, such that is remains inactive until theplunger travels a certain overtravel distance.

It is understood that various mechanisms can be provided that rely onmechanical movement to change the state of a disconnect according to thepresent invention. FIG. 4 shows still another embodiment of a disconnect400 that relies on linear mechanical movement to change the disconnect'sstate. The disconnect 400 comprises a housing 102, inner cup 104 andheader 106, that are arranged to hold the disconnect's inner componentsas described above. A shaft 114 is arranged so that is passes throughthe housing 102; the portion of the shaft extending from the housing isarranged in a bellowed tube 402. In some embodiments, the bellowed tube402 is sealed and mounted to the housing with a seal, and is arranged sothat a linear down force on the tube can cause a corresponding collapseof the tube 402. This collapse in turn causes the shaft to move down tothe connect state. A return up force on the tube 402 causes the returnof the tube 402, and the resulting movement of the shaft causes thedisconnect to return to the disconnect state. As above, many differentmechanisms can be used to cause this linear force, such as a button,handle, or mechanism that translates rotational to linear movement.

FIG. 5 shows another embodiment of a manual disconnect 500 that relieson force applied to a diaphragm structure 502 to change the disconnect'sstate. The disconnect 500 comprises a housing 102, inner cup 104 and aheader 106, that are arranged to hold the disconnect's inner componentsas described above. A shaft 114 is arranged so that it passes throughthe housing 102, and can apply force to diaphragm 502. Diaphragm 502 isa structure that can expand, flex, contract or change shape orconfiguration when force is applied to it. Theexpansion/flexion/contraction and shape/configuration change nature ofdiaphragm 502 can be due to many factors, including but not limited toits shape, physical design, material properties and/or arrangement. Theexpansion/flexion/contraction or change in shape/configuration ofdiaphragm 502 can cause diaphragm 502 to interact with the movablecontact 120, thereby causing it to contact the fixed contacts 122, 124.

Diaphragm 502 can provide leverage, allowing a smaller applied force totranslate into a larger force to affect the movement of moveable contact120. Shaft 114 can be near, part of or physically connected to diaphragm502. In one embodiment, force applied to the center of diaphragm 502causes the diaphragm to flex, causing moveable contact 120 to contactfixed contacts 122, 124. Discontinuing the applied force causesdiaphragm 502 to return to its original configuration, allowing movablecontact 120 to return to the disconnect position. Diaphragm 502 can bemany shapes and made of many different materials. In one embodiment,diaphragm 502 is cylindrical and made of metal such that when asufficient force is applied to the center of diaphragm 502, thediaphragm flexes at the point of application of the force and flexesdownward. In one embodiment, a sufficient amount of force is 40 poundsof pressure. The diameter of diaphragm 502 can be adjusted based on thedistance moveable contact 120 needs to travel (i.e. the contact gap),with a larger diameter beings selected for a greater travel distance.

In one embodiment, diaphragm 502 further comprises a button (not shown)which is a structural feature or area that allows for further controlover the effect an applied force has on diaphragm 502. In oneembodiment, the button is a protrusion from the center of diaphragm 502which would concentrate an applied force to the center of diaphragm 502.

The movement of plunger 110 or shaft 114 can be controlled by variousmanual means which can be attached to a handle mount 504. FIG. 6 shows ahandle mechanism 600 which translates rotational movement of the handle602, to cause linear motion of plunger 110. One such translation means,as discussed above in reference to FIG. 1, includes plunger 110comprising one or more tabs 144 on a surface of the plunger 110 andbeing arranged to cooperate with one or more slots 146. The slot 194 canbe shaped or angled so that as the plunger 110 is rotated, thecooperation of the tabs 144 in the slots 146 causes the plunger 110 tomove linearly within the housing 102; i.e. between the top and bottom ofthe disconnect depending on the direction of rotation. This causes thedisconnect to transition between connect and disconnect states.

Handle mechanism 600 can be arranged such that the rotational movementof handle 602 can have multiple positions, each corresponding todifferent states of connection. In one embodiment, handle mechanism 600has a first position 604 and a second position 606, wherein one positionindicates the manual disconnect is in a connect state and the otherposition indicates that the manual disconnect is in a disconnect state.Handle mechanism 600 can further comprise locking mechanism 608 whichcan lock the position of handle 602 in first position 604. Lockingmechanism 608 can be any means of holding handle 602 in place. In oneembodiment, locking mechanism 608 comprises a hole which is aligned to acorresponding hole in handle 602. A locking means such as a standardpadlock can be inserted through both holes.

FIGS. 7-9 show side, top and bottom views, respectively of oneembodiment of a disconnect 700 with a housing 702, with a manualmechanism 704 that allows for manually changing the state of thedisconnect between connect or disconnect. The mechanism 704 can be usedto provide up/down linear motion, or can be used to provide a rotationalmovement that is translated into linear movement as described above. Themechanism 704 can be used with a mechanical or magnetic feed-through asdescribed above. The disconnect comprises external terminal studs 706,708 for connecting the disconnect to external circuitry.

Although the present invention has been described in considerable detailwith reference to certain preferred configurations thereof, otherversions are possible. The disconnect arrangement can have manydifferent variations. The spirit and scope of the invention should notbe limited to the preferred versions of the invention described above.

I claim:
 1. A manual disconnect, comprising: a hermetically sealedhousing having internal components for changing the state of saiddisconnect between connect and disconnect states, said housingcomprising a cup for holding said internal components, and a headercovering said cup with an airtight seal; terminals electricallyconnected to said internal components for connection to externalcircuitry; and an external manual mechanism for controlling saidinternal components as needed to change the state of said disconnectbetween said connect and disconnect states.
 2. The manual disconnect ofclaim 1, wherein said internal components comprise at least one moveablecontact that moves in response to activation of said external manualmechanism and at least one fixed contact electrically connected to saidterminals.
 3. The manual disconnect of claim 2, wherein said disconnectis in the disconnect state when said at least one moveable contact isnot in contact with said at least one fixed contact and said disconnectis in the connect state when said at least one moveable contact is incontact with said at least one fixed contact.
 4. The manual disconnectof claim 2, said disconnect arranged such that rotational movement ofsaid external manual mechanism causes linear movement of said at leastone moveable contact.
 5. The manual disconnect of claim 2, saiddisconnect arranged such that linear movement of said external manualmechanism causes linear movement of said at least one moveable contact.6. The manual disconnect of claim 2, said disconnect arranged such thatrotational movement of said external manual mechanism causes rotationalmovement of said at least one moveable contact.
 7. The manual disconnectof claim 2, said disconnect arranged such that linear movement of saidexternal manual mechanism causes rotational movement of said at leastone moveable contact.
 8. The manual disconnect of claim 2, wherein saidexternal manual mechanism comprises magnets.
 9. The manual disconnect ofclaim 8, wherein said at least one moveable contact is arranged to movein response to a magnetic field of said magnets.
 10. The manualdisconnect of claim 9, said disconnect arranged such that linearmovement of said external manual mechanism causes linear movement ofsaid at least one moveable contact due to said magnetic field.
 11. Themanual disconnect of claim 1, wherein said hermetically sealed housingis filled with a gas.
 12. The manual disconnect of claim 1, wherein saidhermetically sealed housing is under vacuum conditions.
 13. A manualdisconnect, comprising: a hermetically sealed housing comprising a cupand a header covering said cup with an airtight seal; internalcomponents in said hermetically sealed housing for changing the state ofsaid disconnect between connect and disconnect states, said internalcomponents comprising: a shaft that moves in response to activation ofan external manual mechanism; at least one moveable contact incommunication with said shaft which moves in conjunction with saidshaft; and at least one fixed contact; and terminals electricallyconnected to said fixed contacts for connection to external electricalcircuitry.
 14. The manual disconnect of claim 13, further comprising aplunger in communication with said shaft, wherein said shaft moves inresponse to force applied by said plunger.
 15. The manual disconnect ofclaim 14, wherein said external manual mechanism comprises at least onemagnet and said plunger comprises a material that interacts with themagnetic field of said at least one magnet.
 16. The manual disconnect ofclaim 13, further comprising a bellowed tube on said housing andsurrounding said shaft, said bellowed tube arranged such that a lineardownward force on said tube causes said tube to collapse and a linearupward force causes said tube to return to its original configuration,wherein said shaft moves in conjunction with said bellowed tube.
 17. Themanual disconnect of claim 13, said disconnect arranged such thatrotational movement of said external manual mechanism causes linearmovement of said shaft.
 18. The manual disconnect of claim 17, whereinsaid external manual mechanism comprises a handle mechanism capable ofbeing manipulated and placed in two positions, wherein one positioncorresponds to said disconnect being in a disconnect state and the otherposition corresponds to said disconnect being in a connect state. 19.The manual disconnect of claim 18, wherein said external manualmechanism further comprises a locking mechanism to lock said handle inone of said two positions.
 20. A method for manually connecting anddisconnecting an electrical circuit, said method comprising the stepsof: 1) providing a hermetically sealed manual disconnect comprisinginternal components for changing the state of said disconnect betweenconnect and disconnect states, terminals electrically connected to saidinternal components for connection to said electrical circuit and anexternal manual mechanism for controlling said internal components asneeded to change the state of said disconnect between said connect anddisconnect states; 2) connecting said terminals to said electricalcircuit; and 3) activating said external manual mechanism to change thestate of said disconnect.